Azabicyclic alkaloids chiral

The pyrrolidine synthon (48) is useful for the chiral synthesis of pyrrolizidine, pyrrolidine, indolizidine and azabicyclic alkaloids (see Scheme 23). 

Similarly, chiral bases have found use in the preparation of building blocks for synthesis of alkaloids. A range of A-protected azabicyclic ketones was deprotonated to yield corresponding silylenol ethers (Scheme 30)68-70. The highest ee (93%) was obtained using 42 under internal quench conditions. These chiral ethers found use as key intermediates in the preparation of naturally occurring alkaloids. 

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